Confronting GRB prompt emission with a model for subphotospheric dissipation

Abstract

The origin of the prompt emission in gamma-ray bursts (GRBs) is still an unsolved problem and several different mechanisms have been suggested. Here we fit Fermi GRB data with a photospheric emission model which includes dissipation of the jet kinetic energy below the photosphere. The resulting spectra are dominated by Comptonization and contain no significant contribution from synchrotron radiation. In order to fit to the data we span a physically motivated part of the model's parameter space and create DREAM ($\text{Dissipation with Radiative Emission as A table Model}$), a table model for $XSPEC$. We show that this model can describe different kinds of GRB spectra, including GRB 090618, representing a typical Band function spectrum, and GRB 100724B, illustrating a double peaked spectrum, previously fitted with a Band+blackbody model, suggesting they originate from a similar scenario. We suggest that the main difference between these two types of bursts is the optical depth at the dissipation site.

6 pages, 2 figures, accepted to MNRAS as a Letter

References in corpus (7)

• Detection of a Thermal Spectral Component in the Prompt Emission of GRB 100724B
• GRB110721A: An extreme peak energy and signatures of the photosphere
• Temporal Evolution Of Thermal Emission From Relativistically Expanding Plasma
• Prompt emission spectra from the photosphere of a GRB
• The width of gamma-ray burst spectra
• Evidence for jet launching close to the black hole in GRB 101219B - a Fermi GRB dominated by thermal emission
• An Observed Correlation Between Thermal and Non-Thermal Emission in Gamma-Ray Bursts

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